[1] Sungkyunkwan Univ, Kangbuk Samsung Hosp, Sch Med, Dept Internal Med, 108 Pyung Dong, Seoul 110746, South Korea
[2] CHA Univ, CHA Bundang Med Ctr, Ctr Digest Dis, 59 Yatap Ro, Songnam 463712, Gyeonggi Do, South Korea
[3] Hanyang Univ, Guri Hosp, Dept Internal Med, Guri, South Korea
[4] Soonchunhyang Univ, Sch Med, Ctr Digest Dis, Dept Internal Med, Bucheon, South Korea
[5] Soonchunhyang Univ, Sch Med, Res Inst, Bucheon, South Korea
[6] Wonkwang Univ, Coll Med, Digest Dis Res Inst, Dept Internal Med, Iksan, South Korea
[7] Kyung Hee Univ, Kyung Hee Univ Hosp Gang Dong, Sch Med, Dept Internal Med, Seoul, South Korea
[8] Yonsei Univ, Coll Med, Dept Internal Med, Div Gastroenterol, Seoul, South Korea
[9] Yeungnam Univ, Coll Med, Dept Internal Med, Div Gastroenterol & Hepatol, Daegu, South Korea
[10] Ewha Womans Univ, Sch Med, Dept Internal Med, Seoul, South Korea
[11] Soonchunhyang Univ, Coll Med, Dept Med, Div Gastroenterol, Cheonan, South Korea
[12] Keimyung Univ, Sch Med, Dept Internal Med, Div Gastroenterol, Daegu, South Korea
[13] Kyung Hee Univ, Sch Med, Dept Internal Med, Seoul, South Korea